Scientists model how saltwater behaves deep below Earth’s surface

Scientists estimate that the Earth's mantle holds as much water as all the oceans on the planet, but understanding how this water behaves is difficult. Water in the mantle exists under high pressure and at elevated temperatures, extreme conditions that are challenging to recreate in the laboratory. That means many of its physical and chemical properties-relevant to understanding magma production and the Earth's carbon cycle-aren't fully understood. If scientists could better understand these conditions, it would help them better understand the carbon cycle's consequences for climate change. A team led by Profs. Giulia Galli and Juan de Pablo of the University of Chicago's  Pritzker School of Molecular Engineering and by computer scientist François Gygi of the University of California, Davis has created complex computer simulations to better understand the properties of salt in water under mantle conditions. By coupling simulation techniques developed by the three research groups and using sophisticated codes, the team has created a model of saltwater based on quantum mechanical calculations. Using the model, the researchers discovered key molecular changes relative to ambient conditions that could have implications in understanding the interesting chemistry that lies deep beneath the Earth's surface.